Performance Improvements: GPU + FFMPEG6.0 + Pillow SIMD + Double Buffer = 🚀

[time4tea]

In the soon-to-be-released next version of gopro-dashboard, we've managed to figure out the changes so that we can support nvidia GPUs in an almost-optimal way. Using the decoding, format conversion, overlay and encoding all in the GPU, along with the use of Pillow-SIMD - we can now achieve an almost unbelievable 120fps.

This equates to being able to render 20mins of footage with an overlay in only 1m40s... about 12x real-time.

This is a huge improvement from initial versions of the software. 🎉 and we're really excited by it.

These tests were done using Python3.11, ffmpeg 6.0, Linux, NVidia 3060 GFX Card, Pillow SIMD, and a 1920x1080 GoPro movie, using M2 drive, and --double-buffer mode

[time4tea]

This is now released in version 0.93.0 - please do read PERFORMANCE_GUIDE.md